Patent GB-1141121-A (GB)
Title: Foam bound fabrics
IPC: D04H1/68
Filed: 1966-01-11
Abstract: 1,141,121. Treating textiles. GENERAL TIRE & RUBBER CO. 11 Jan, 1966 [13 Jan., 1965], No. 1216/66. Heading D1P [Also in Division B2] A process for producing a foamed-impregnated fabric comprises depositing liquid polyurethane-foam-forming reactants which may have been reacted to form a pre-polymer, on a sheet of fibrous material causing or allowing the deposited reactants to foam and mechanically introduce reactants into the fabric sheet to impregnate substantially the entire fabric with reactants by subjecting the fabric to pressure after deposition but before completion of foaming, curing the foam in situ to embed the fibres in an open-cell foam matrix and compacting foam impregnated fabric before completion of the cure, said reactants comprising an organic polyisocyanate having 2 to 3 isocyanato groups, a catalyst, and a cross-linking agent containing active hydrogen groups. The fabric may be of nylon, rayon, silk, wool, polyester, paper, cotton, glass, horse hair, cow hair, coconut fibres or mixtures thereof and may be non woven. The isocyanate may be an aliphatic isocyanate having 2-10 carbon atoms in a straight chain between the isocyanato groups as in hexamethylene diisocyanate, tetramethylene diisocyanate and decamethylene diisocyanate and cycloaliphatic compounds such as hydrogenated bis-phenyl diisocyanate, cyclohexylene - 1,2 - diisocyanate or cyclo-hexylene - 1,2 - diisocyanate. Aromatic diisocyanates may be used and numerous examples are given. The cross-linking agents have active hydrogen atoms and may be a hydroxyl terminated polyether or polyester of molecular weight 500 or more. Polyoxy alkylenes may be used. The polyether may be obtained by polymerisation of ethylene oxide, propylene oxide, butylene oxide, styrene oxide, epichlorohydrin or substituted oxetanes. The polyesters may be prepared for my dicarboxylic acids of 4-8 carbon atoms, such as adipic acid or sebacic acid with polyhydric alcohols such as ethylene glycol, 1,4/butylene glycol, propylene glycol or 1, 6-hexane diol, triols, tetrols or polyglycols. An activator mixture such as water, a tertiary amine or an organometallic compound may be present. The blowing agent may be a fluorinated and chlorinated hydrocarbon of b.p. below 150‹C. Specified are trichloromonofluoromethane, toluene, benzene, pentane, neopentane and hexane. Surfactants, silicone block polymers, antioxidants, antidegradants, organic phosphites and a chloronated organic phosphites may be present. A top coat may be applied to the fibrous mass subsequent to impregnation and prior to curing. Such top-coat contains a polyvinyl resin compound and a polyurethane such as a polyester urethane or polyether urethane. The polyvinyl compound may be partially hydrolyzed vinyl chloride/vinyl acetate copolymer, a copolymer of vinyl chloride, vinyl acetate and maleic acid, a co-polymer of vinyl chloride and beta-hydroxyethyl acrylate or a co-polymer of vinyl chloride, methylmethacrylate and beta-hydroxy-propyl acrylate. The foam-forming mixture may be applied by roller coating or from a nozzle and the impregnation may be carried out by compressing between rollers. The top coat may be applied by knife coating. A continuous mode of operation is described, wherein the compacting includes a compacting step which interacts the curing of the foam.